PubMed:: "Influenza Vaccines"[Mesh] OR vaccin*[tiab] OR immunis*[tiab] OR immuniz*[tiab] OR tiv[tiab] OR laiv[tiab] OR "caiv t"[tiab];; Embase.com:: 'influenza vaccine'/exp OR 'preventive health service'/exp OR vaccin*:ab,ti OR immunis*:ab,ti OR immuniz*:ab,ti OR tiv:ab,ti OR laiv:ab,ti OR 'caiv t':ab,ti OR celvapan:ab,ti OR focetria:ab,ti OR celtura:ab,ti OR prepandrix:ab,ti OR arepandrix:ab,ti OR fluzone:ab,ti OR vaxigrip:ab,ti OR influject:ab,ti OR fluvirin:ab,ti OR agriflu:ab,ti OR optaflu:ab,ti OR influvac:ab,ti OR flumist:ab,ti OR fluarix:ab,ti OR flulaval:ab,ti OR afluria:ab,ti;; Cochrane Library:: vaccin* OR immunis* OR immuniz* OR tiv OR laiv OR "caiv t" OR celvapan OR focetria OR celtura OR prepandrix OR arepandrix OR fluzone OR vaxigrip OR influject OR fluvirin OR agriflu OR optaflu OR influvac OR flumist OR fluarix OR flulaval OR afluria
